Refillable fuse



May 13, 1924. 1,494,141

E. w. SNOW REFILLABLE FUSE Filed July 28, 1.920

mun-mun INVENTOR. 277%655 WSizazu ATTORNEY.

tion has been perfec Patented May'13, 1924-.

UNI-TED STATES PATENT OFFICE.

ERNEST W. SNOW, 0F RDC HESTER NEW YORK.

BEFILLABLE FUSE.

'Application filed July 28,

To all whom it may concern:

Be itknownthat I, ERNEST W. SNOW, a citizen of the United States, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Refillable Fuses; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference nu- .merals marked thereon.

My invention relates to electric fuses or more (particularly-to those of the refillable cartri ge type which comprise a tube of insulating or refractory material containin a fuse strip provided at its ends with'meta members which are adapted to clamp the fuse strip within the insulating tube, co-

operate with clamping or contactingmeansto form an electrical .connection for the passagge of current, and be demountable to env e renewing of the fuse strip after burning. The object of this invention is to provide an improved fuse which is economical of construction, easy to assemble,

-Figure 3 is a section on the line 3--3f of Figure 1.

Figure 4 is an end view of Figure -1. Fi ure 5 is also an end viewof Fi ure 1 wit the adljacent end cap or nut and use strp remove 1 1m ilar reference characters throughout the several views indicate the same parts. In order to achieve a simplification in construction and number of (parts while at the same time possessing an fulfilling the usual re uirements of refillable electric fuses of t e cartridge type such as ready demountabilit and the maintenance of good electrica contact the present invenmi In the drawings 1920. Serial No. 899,527.

the numeral 10 designates a tube of'insulating or refractory material which is adapted to contain the usual fuse strip 11. As is common in the art, the fuse strip 11 may be provided with a reduced portion 12 wherein rupture occurs and the tube 10 may or may not contain some suitable filler surrounding the fuse strip. Provided at each end of the tube 10 are end members or ferrules 13 and 14 of metal or other suitable electric current conducting material,

which are preferably. provided with 'inter nal shoulders 15 for cooperation with the ends of the insulatin tube 10. The ferrules'13 and 14 may be secured to the insulating tube by any suitable means butfor purposes of illustration, I have s ownthemseoured b means of'stamped out lugs 16 which firm y osition the ferrules oil the ends of the tu e. Each ferrule is pro vided with an outwardly rojecting ortion I or cylindrical tongue 17 0 reduced diameter cut away adjacent its base or which is longitudinally or axially rooved, slotted or otherwise provided wit a lateral opening at 18 for the reception of an end of the,

fuse strip 11. Each ferrule is provided" with an end cap or nut 19 the same diameter as the main body p0r tion of the ferrule, and provided interiorly thereof with screw threads 20 or other see; curing means cooperating with some form; of securing means 21 on the cylindrical} us .17 whereby the end cap 19 is adapted rml position the bent over portion 23 of the f tion 22 of the form e ad'acent or surrounding the. outwardly pro ecting ortion 17. Inorder to allow the nut 19 to e screwed up against the shoulder 22, the base ofthe (we 18 and that portion 24 of the shouler 22 which forms a seat for the fuse strip ton to may. be out away or counter-sunk below the shoulder 22 b an amount less than the preferably of,

use strip a ainst the shoulder porthickness of t e fuse strip in order that the end cap fuse strip in cooperate wit the shoulder portion 22. The bent back end of the fuse strip 25 may still securely clamp the affords a convenient place-for marking the size or'capacity of the strip whichmag be readily seen when the fuse is assem led, as shown in Fi re 1. Each nut 19'may be provided wit an aperture or vent 26 'inorder to allow the escape of heated gases when'the fuse strip blowrfrom an overlace and at the same time load of current. In order to provide for the use of a screw driver or other tool for disconnecting the end caps, a groove 27 is provided if desired.

Among the advantages of my improved fuse may be enumerated the simplicity and rigidity of construction. By having the fuse strip firmly clamped against the shoulder 22, a rigid abutment, is provided therefor which is not liable to flex or bend. Having the end caps of the same diameter as the main body portion of the ferrule results in a neat appearance as well as a saving of metal. Each end connection for the insulating tube 10 comprises a minimum number of parts, namely the fuse strip and two clamping members between which the fuse strip is secured. With the fuse 'stri seated in a groove 18' and bent bac as shown there is no likelihood of the end of the fuse closing the aperture 26. With the type of end caps shown facility of demountability is assured and it is very easy to tell whether the fuse is blown or not. The adaptability of the end of the fuse strip 25 to be used for marking the size or capacity of the fuse enables fuse strips of difierent capacities to be used and also insures a certain indication of the size 'throu h the ready visibility of the back turne end 25. The protruding end of the fuse strip affords'an easy means of determining whether one or more than one thickness or fuse strip is contained within the cartridge or receptacle.

I clalm as my invention:

1. In a fuse, the combination with an insulating tube of a metal end member secured to the tube having a threaded projecting portion havin a lateral opening at the bottom thereof an a shouldered portion -adjacent the projecting portion, a fuse within the opening of the projecting: portion and a'clampin means in cooperation with the threads 0 the projecting portion to clamp the fuse securely against the shoul- 3. In combination a refractor tube of insulating material, an end ferru e secured to the tube and having an externally threaded projecting portion of reduced diameter and a shoulder on the ferrule around the base of the projecting portion, an axial groove in said projecting portion extending through said shoulder, a perforated cup.

shaped cap of the same diameter as the ferrule in engagement with said projecting portion and adapted to clamp a fuse strip against said shoulder.

4. In a fuse the combination with an insulating tube of a conducting ferrule surrounding and secured to the tube and havceive a fuse stri and a shoulder on the ferrule around t e base of said projecting portion, the shoulder bein slightly countersunk in alinement with t e groove in the projectin portion but to a depth of less than the t ickness of the fuse strip used and clamping means for holdin the fuse strip in position against the shoulder.

ERNEST w. SNOW.

.ing a projecting portion having a lateral opening adjacent the base thereof to re- 

